1. Field of the Invention
The present invention relates to the installation of a cold water conduit on the floor of a continental shelf for use with Ocean Thermal Energy Conversion (OTEC) power plants. More particularly, the invention is concerned with the installation of larger than ever before installed cold water conduits being guided into place and secured to a marine railway system.
The high cost and dwindling supply of easily obtainable fossil fuels has created an intense interest in alternative sources of energy. One such alternative energy source involves the utilization of the temperature differential between the warm surface seawater and the subsurface seawater. This general concept is known as ocean thermal energy conversion or "OTEC".
In the operation of an OTEC power plant, warm surface seawater is used to vaporize a working fluid. The vapor is used to drive a turbine generator in much the same way steam is used to drive turbine generators, which ultimately produce electricity. After the vapor has passed through the turbines, cool subsurface seawater is used to condense the vapor, thereby completing the working fluid cycle. The cool subsurface seawater required for the process is located roughly 1500 to 3000 feet below the water surface depending on the latitude of the OTEC power plant. In the design of many OTEC power plants, it is necessary to pump large quantities of this cool subsurface seawater to the surface. To accomplish this it is envisioned that a long pipe commonly referred to as a "cold water conduit" will be used, said conduit to extend from the surface downward roughly 1500 to 3000 feet deep. It is anticipated that the cold water conduit must be approximately 5 to 120 feet in diameter for OTEC power plants from 1 to 400 MW respectively.
The need for such a huge conduit presents several severe problems. The conduit must be fabricated, installed, and secured so that it will be able to withstand the tremendous dynamic current loads. Other problems involve the method of installing such a large conduit and maintaining its position with respect to the OTEC plant located on the surface.
The present invention also minimizes the harm to the marine ecological system since it requires minimal disturbance of the ocean floor. All underwater operations can be monitored by the use of underwater cameras which miminizes the need for underwater personnel. The installation process proceeds from shallow waters thereby reducing the environmental forces on the work vessels and installation operation.